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TBar Send message Joined: 22 May 99 Posts: 5204 Credit: 840,779,836 RAC: 2,768 |
I'm seeing results that seem to imply AP tasks run against CPUs award much lower credit than those run by Two GPUs. There is a bit of blanking, but at first look it seems some of the longer CPU tasks also pay less credit. I brought my ATI cards out of retirement just to run some APs, but it seems they are getting robbed. The blanked tasks take longer on the ATIs, but if the CPU takes a short time then the ATIs get much less credit for a longer task. Take a look at some of the run-times verses credit, https://setiathome.berkeley.edu/results.php?hostid=6796475&offset=60&appid=20Yes, everything is running smoothly now. This one is more depressing than most, it's a longer than normal time, but scores a faction of normal; Task Computer Sent Time reported Status Run time CPU time Credit Application 6573740896 8260247 18 Apr 2018, 1:17:28 UTC 18 Apr 2018, 7:47:00 UTC Completed and validated 14,620.79 14,551.17 163.35 AstroPulse v7 v7.03 (sse2) windows_x86_64 6573740897 6796475 18 Apr 2018, 1:17:28 UTC 18 Apr 2018, 6:51:54 UTC Completed and validated 2,132.81 441.49 163.35 AstroPulse v7 Anonymous platform (ATI GPU) Blah! 131.04 pts for a normal AP, https://setiathome.berkeley.edu/workunit.php?wuid=2941091313 |
rob smith Send message Joined: 7 Mar 03 Posts: 22530 Credit: 416,307,556 RAC: 380 |
One of the (major) deficiencies of CreditScrew is that is will award to lower calculated score to both parties. And it doesn't play well with GPUs in general, or with GPUs doing multiple tasks in particular. Bob Smith Member of Seti PIPPS (Pluto is a Planet Protest Society) Somewhere in the (un)known Universe? |
juan BFP Send message Joined: 16 Mar 07 Posts: 9786 Credit: 572,710,851 RAC: 3,799 |
In your, mine and allmost all opinion but not in the opinion of CreditScrew. |
Keith Myers Send message Joined: 29 Apr 01 Posts: 13164 Credit: 1,160,866,277 RAC: 1,873 |
I'm sure there is a good reason why one was assigned to the CPU (SSE2) while the other was assigned to the GPU (opencl), but still.. ! I can't seem to grab those tasks to get a look a their estimated flops. Would be one way to point at what credit should be awarded. Credit is handled by the CreditNew award mechanism which is admittedly flawed as most will attest. It was based originally on the number of Cobblestones used to compute a task. The same amount of cobblestones would be used to compute the same task whether it was computed on a gpu or cpu. The gpu is the more powerful computer and so would run the task in a shorter wall clock time compared to the slower cpu which would need a much longer amount of wall clock time to accumulate the same number of Cobblestones. That base mechanism was the original start of CreditNew. But then CreditNew got corrupted about 8 years ago by the modification of the award mechanism based on theoretical AVX compute profiling. And it has been debased to CreditScrew ever since. Can't do anything about it so just accept it. Seti@Home classic workunits:20,676 CPU time:74,226 hours A proud member of the OFA (Old Farts Association) |
TBar Send message Joined: 22 May 99 Posts: 5204 Credit: 840,779,836 RAC: 2,768 |
Seems there is also a hit to the MB Arecibo tasks Credit. My one Mac has been running mostly Arecibo Non-APs tasks for the past few days. Usually when that happens it will be up in the Mid-90k range, However, it's currently in the Lower 80k range. The only reason that could be, would be the Tons of VLARs it's been running. So as usual, any change to Credit awarded is Negative. It's ALWAYS Negative. My Theory is CreditFew is actually designed to consistently award Fewer and Fewer awards, it certainly preforms that way anyway. |
Bill G Send message Joined: 1 Jun 01 Posts: 1282 Credit: 187,688,550 RAC: 182 |
With regard to the length of time it takes to do an AP: As a general rule when run on the CPU instead of the GPU it takes about 7 times longer. They both will give the same amount of credit it seems. The only way that I know of around that is to not run APs on the CPU. (I think the the CPU credit is just about the same as non-ap work despite the time difference of AP to non-AP work. Whithout doing massive amounts of data averaging that is my take on it.) SETI@home classic workunits 4,019 SETI@home classic CPU time 34,348 hours |
Stephen "Heretic" Send message Joined: 20 Sep 12 Posts: 5557 Credit: 192,787,363 RAC: 628 |
Seems there is also a hit to the MB Arecibo tasks Credit. My one Mac has been running mostly Arecibo Non-APs tasks for the past few days. Usually when that happens it will be up in the Mid-90k range, However, it's currently in the Lower 80k range. The only reason that could be, would be the Tons of VLARs it's been running. So as usual, any change to Credit awarded is Negative. It's ALWAYS Negative. My Theory is CreditFew is actually designed to consistently award Fewer and Fewer awards, it certainly preforms that way anyway. . . Exactly, any change in work type and the credit awarded across the board will decrease .... . . I will say however that the decline with the Arecibo VLARs on nvidia GPUs is slower than I had expected. Slow but inexorable. Stephen :( |
juan BFP Send message Joined: 16 Mar 07 Posts: 9786 Credit: 572,710,851 RAC: 3,799 |
So as usual, any change to Credit awarded is Negative. To try to mantain our RAC we need to put to work more and more powerfull hosts. Maybe that's the hidden idea behind CreditScrew (or CreditFew) My +/- 190K/host is now producing <160K/day. |
Richard Haselgrove Send message Joined: 4 Jul 99 Posts: 14679 Credit: 200,643,578 RAC: 874 |
No matter how the tasks are built, one that runs for over 5hrs should pay more than one that takes 15 minutes, in my opinion.A workunit is a fixed amount of work. Faster hardware (GPU) will complete it more quickly than slower hardware (CPU). I don't see anything wrong with that - the credit is awarded for the work (see definition of cobblestone). |
Jord Send message Joined: 9 Jun 99 Posts: 15184 Credit: 4,362,181 RAC: 3 |
So I guess this isn't good for getting data from Arecibo either: Puerto Rico is Once Again Hit by an Islandwide Blackout An electrical contractor working to restore power in Puerto Rico accidentally knocked out a major transmission line on Wednesday, leaving the entire island without power nearly seven months after Hurricane Maria destroyed the electrical grid. |
Richard Haselgrove Send message Joined: 4 Jul 99 Posts: 14679 Credit: 200,643,578 RAC: 874 |
I thought the last we heard, the Arecibo radio telescope was limping along on fossil (diesel) generators, independently of the island's civilian electricity network? I'll leave you to think about whether scientists should isolate themselves like that, but it happens. |
Keith Myers Send message Joined: 29 Apr 01 Posts: 13164 Credit: 1,160,866,277 RAC: 1,873 |
With regard to the length of time it takes to do an AP: I've been rescheduling any AP CPU tasks to GPU simply because of the efficiency gain. The side benefit it seems is that the scheduler now thinks the CPU is the most efficient compute device and it seems it has been loading me up with tons of AP CPU tasks. Which only means more AP tasks for the gpus and more credit. I have had upwards of 30+ AP tasks on all hosts now for a couple of weeks at all times. Seti@Home classic workunits:20,676 CPU time:74,226 hours A proud member of the OFA (Old Farts Association) |
TBar Send message Joined: 22 May 99 Posts: 5204 Credit: 840,779,836 RAC: 2,768 |
Have you run the math on the machines running the Special App? I think you will find the Faster GPUs actually Lose Credit when running APs. They produce More Credit by running normal Arecibo MBs than APs. The VLARs are about even. So, you are going thru a lot of trouble, and destroying your APR, for nothing. I've long recommended the Faster GPUs running the Special App Avoid APs, and leave them for the slower machines. You'll notice my fastest machine doesn't run APs. |
Keith Myers Send message Joined: 29 Apr 01 Posts: 13164 Credit: 1,160,866,277 RAC: 1,873 |
Have you run the math on the machines running the Special App? I think you will find the Faster GPUs actually Lose Credit when running APs. They produce More Credit by running normal Arecibo MBs than APs. The VLARs are about even. So, you are going thru a lot of trouble, and destroying your APR, for nothing. I've long recommended the Faster GPUs running the Special App Avoid APs, and leave them for the slower machines. You'll notice my fastest machine doesn't run APs. All this may be true. But I just have a big bother with inefficiency. It just bugs me to see a cpu core tied up for 4 hours with a AP task when it could be done in 12 minutes on the gpu. As you say, it likely is hurting my RAC. And it definitely is messing with the cpu APR. Seti@Home classic workunits:20,676 CPU time:74,226 hours A proud member of the OFA (Old Farts Association) |
betreger Send message Joined: 29 Jun 99 Posts: 11416 Credit: 29,581,041 RAC: 66 |
IMO if I cared about credit I wouldn't run Seti at all. If you want credit there are projects such as Collatz that award insane credit. That is aside of my opinion that trying to disprove what seems to be a logical regression by brute force is also a waste of electricity. |
Stephen "Heretic" Send message Joined: 20 Sep 12 Posts: 5557 Credit: 192,787,363 RAC: 628 |
No matter how the tasks are built, one that runs for over 5hrs should pay more than one that takes 15 minutes, in my opinion.A workunit is a fixed amount of work. Faster hardware (GPU) will complete it more quickly than slower hardware (CPU). I don't see anything wrong with that - the credit is awarded for the work (see definition of cobblestone). . . Sadly Richard, while what you say is true that credit is supposed to represent the actual work done, in reality there is little to no consistency and certainly not any connection to the defined cobblestone ... Stephen :( |
Stephen "Heretic" Send message Joined: 20 Sep 12 Posts: 5557 Credit: 192,787,363 RAC: 628 |
Have you run the math on the machines running the Special App? I think you will find the Faster GPUs actually Lose Credit when running APs. They produce More Credit by running normal Arecibo MBs than APs. The VLARs are about even. So, you are going thru a lot of trouble, and destroying your APR, for nothing. I've long recommended the Faster GPUs running the Special App Avoid APs, and leave them for the slower machines. You'll notice my fastest machine doesn't run APs. . . Yep, exactly what I have found, on good GPUs running a special sauce form of CUDA you do better with tasks other than AP. But Keith is also running Windows boxes and I think that is where he is benefitting. Stephen . . |
Stephen "Heretic" Send message Joined: 20 Sep 12 Posts: 5557 Credit: 192,787,363 RAC: 628 |
IMO if I cared about credit I wouldn't run Seti at all. If you want credit there are projects such as Collatz that award insane credit. That is aside of my opinion that trying to disprove what seems to be a logical regression by brute force is also a waste of electricity. . . Well there's Einstein@home, they give good credit and are doing useful work. Stephen . |
Sirius B Send message Joined: 26 Dec 00 Posts: 24912 Credit: 3,081,182 RAC: 7 |
Ah but everyone wants to be the 1st in finding E.T. so they can tell him to phone home :-) |
betreger Send message Joined: 29 Jun 99 Posts: 11416 Credit: 29,581,041 RAC: 66 |
. . Well there's Einstein@home, they give good credit and are doing useful work. Yep I'm there and maintain a RAC ~500K, as an aside a couple of days ago Richard posted that he thought E@H probably was truest to the cobblestone credit issue but I don't crunch there for the credit. |
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